Mammoth Cave National Park is a U.S. National Park in central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world. The official name of the system is the Mammoth Cave System for the ridge under which the cave has formed. The park was established as a national park on July 1, 1941. Legend has it that the first European to discover Mammoth Cave was John Houchin, in 1797. While hunting, Houchin pursued a wounded bear to the cave's large entrance opening near the Green River.